JP2003188643A - Antenna assembly and array antenna using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid dropping the gain of an antenna assembly having broadband antenna characteristics over a wide angle of its radiation pattern, thus obtaining a wide width of beam over a wide band. <P>SOLUTION: The antenna assembly comprises: a plurality of taper slot antennas composed of antenna elements having conductors formed on a dielectric substrate and taper slots formed into the conductors such that the slot width expands toward the ends of the dielectric substrate, micro striplines for feeding high frequency signals to the antenna elements, and transducers for transmitting the high frequency signals fed from the micro striplines onto the taper slots after mode conversion thereof; and a distributor for distributing and feeding the high frequency signals to the taper slot antennas disposed radially with the dielectric substrate ends disposed along a circular arc. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device used in a communication system or a radar system and an array antenna using the same.

[0002]

2. Description of the Related Art Heretofore, a taper slot antenna has been widely known as an antenna device having a broadband antenna characteristic. This taper slot antenna is
An antenna element is formed on the antenna substrate, which is composed of a tapered slot having a shape that gradually expands toward the end of the substrate. For example, Japanese Patent Laid-Open No. 2000-196344 describes an antenna device that feeds power to such an antenna element via a slot line and a coplanar line.

FIG. 5 is a perspective view showing a general taper slot antenna having an antenna element as described above. In FIG. 5, reference numeral 21 is a dielectric substrate, 22 is a metal conductor portion formed on the dielectric substrate 1, 23 is formed on the metal conductor portion 22, and the width of the dielectric substrate 21 is increased toward the end portion. An antenna element having a tapered portion 24 that gradually expands, 25 is a microstrip line, and 26 is a microstrip-slot conversion unit that mode-converts the high-frequency signal supplied by the microstrip line 25 and transmits it to the slot line 27 of the antenna element 3. , 28 are coaxial connectors for supplying a high frequency signal supplied from an external device or the like to the microstrip line 25.

The high frequency signal fed from the coaxial connector 28 is supplied to the microstrip-slot converter 26 via the microstrip line 25. The high frequency signal supplied to the microstrip-slot converter 26 is mode-converted on the slot line 27 and transmitted to the taper portion 24 of the antenna element 23 via the slot line 27. The tapered portion 24 has a structure in which the width thereof gradually widens toward the end portion of the dielectric substrate 21, and a traveling wave toward the end portion of the dielectric substrate 21 is formed on the antenna element 23.

[0005]

Since the conventional antenna device is constructed as described above, impedance matching can be achieved over a wide band, but the antenna device alone has a wide-angle radiation pattern drop in the high frequency range. ,
There is a problem that the beam width becomes narrow. That is,
The main part that contributes to the radiation of the antenna device is the opening A of the antenna element 23 at the end of the dielectric substrate 21, but in reality, radio waves are also emitted from the tapered portion 24 other than the opening A of the antenna element 2. The wave source is radiated and the wave source is distributed in the vicinity B of the end portion of the dielectric substrate 21 extending from the slot line 7 to the taper portion 24, and the antenna device behaves like an end fire array. Then, this phenomenon becomes remarkable in the high frequency region where the length of the taper portion 24 in the longitudinal direction becomes long with respect to the wavelength, and therefore, in the high frequency region, the beam width becomes narrow.

FIG. 6 is a radiation pattern diagram schematically showing a radiation pattern of the conventional antenna device shown in FIG. Figure 5
As shown in, when the antenna device behaves like an end fire array, a wide-angle gain drop occurs, and the actual radiation pattern 29 is formed with a narrow beam width with respect to the desired radiation pattern 30. It

The present invention has been made in order to solve the above problems, and in an antenna device having a wide band antenna characteristic, a drop in gain at a wide angle of a radiation pattern is prevented, and a wide beam is spread over a wide band. It is an object of the present invention to obtain an antenna device having a novel structure capable of obtaining a width.

It is another object of the present invention to obtain an array antenna having a novel structure, which has a small influence on the radiation pattern by using such an antenna device.

[0009]

According to another aspect of the present invention, there is provided an antenna device, wherein a conductor portion is formed on a dielectric substrate, and the conductor portion comprises a tapered slot that widens toward an end portion of the dielectric substrate. An element, a microstrip line for supplying a high-frequency signal to the antenna element, and a taper slot antenna section having a conversion section for mode-converting and transmitting the high-frequency signal supplied by the microstrip line on the taper slot; A plurality of taper slot antenna parts are arranged radially so that the ends of the body substrate are arranged in an arc shape, and a distributor that distributes a high-frequency signal to the plurality of taper slot antenna parts and supplies the power. It is a thing.

In the antenna device according to the second aspect of the present invention, the distributor distributes the high-frequency signal fed to the plurality of taper slot antenna parts into equal amplitude and equal phase.

In the antenna device according to a third aspect of the present invention, the plurality of taper slot antenna parts are constituted by three or more taper slot antenna parts.

The antenna device according to a fourth aspect of the present invention is arranged such that an angle formed between the tapered slot antenna portions of the plurality of tapered slot antenna portions is within 45 degrees.

According to a fifth aspect of the present invention, there is provided an antenna device, wherein a fan-shaped biconical antenna portion having a tapered notch portion formed in an arc portion is connected to the tapered notch portion of the biconical antenna portion. A slot portion formed on the opposite side of the circular arc portion, a feeding line for supplying a high frequency signal to the slot portion, and a conversion for mode-converting and transmitting the high frequency signal supplied by the feeding line to the slot portion. And a section.

An array antenna according to the invention of claim 6 is
The antenna device according to claim 1 or 5 is arranged in an array.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 of the present invention will be described below with reference to FIGS. 1 and 2.
1 is a configuration perspective view showing an antenna device according to a first embodiment of the present invention. In FIG. 1, 1 is a dielectric substrate,
2 is an antenna having a metal conductor portion formed on the dielectric substrate 1 and 3 is formed on the metal conductor portion 2 and having a taper portion 4 in which the slot width gradually widens toward the end of the dielectric substrate 1. An element 5, a microstrip line, and 6 a microstrip-slot converter (hereinafter, simply referred to as a converter) that mode-converts a high-frequency signal supplied by the microstrip line 5 and transmits it on the slot line 7 of the antenna element 3. ), 8 is a power feeding portion to which a high frequency signal is fed by a distributor described later, 9 is a high frequency signal input from an input end 10, and the dielectric substrate 1, the metal conductor portion 2, the antenna element 3, the microstrip line 5, the conversion A distributor for distributing a high-frequency signal to each taper slot antenna unit 11 including a power supply unit 6 and a power supply unit for power supply, and 12 is a power supply unit for each taper slot antenna unit 11. It is connected to the part 8, the distributor 9
Is a power feeding line that feeds the high frequency signal distributed by the above to the power feeding unit 8 of each taper slot antenna unit 11.

As shown in FIG. 1, each taper slot antenna section 11 has substantially the same structure and is arranged radially around the feeding section 8 to radiate an end portion of the dielectric substrate 1, that is, a radio wave. The opening 13 of the tapered slot antenna section 11 is provided so as to be arranged on the arc line 14. Further, in the antenna device according to the first embodiment, the three taper slot antenna parts 11 are radially arranged so that the angles formed between the respective taper slot antenna parts 10 are about 45 degrees. However, if the angle formed between the taper slot antenna parts 11 (hereinafter referred to as the arrangement angle) is 45 degrees or less, the two taper slot antenna parts 11 or the number of the taper slot antenna parts 11 can be increased. is there. In addition, it is desirable that these arrangement angles be within 45 degrees.

Next, the operation will be described with reference to FIG.
The high frequency signal input to the input terminal 10 of the distributor 9 is distributed by the distributor 9 to the same amplitude and the same phase, and
Power is fed to the feeding portion 8 of each taper slot antenna portion 11 via the. The high-frequency signal fed to each feeding unit 8 is supplied to the converting unit 6 via the microstrip line 5, and each converting unit 6 performs mode conversion on the slot line 7. The signal whose mode has been converted in each converter 6 is transmitted through the slot line 7 and the tapered portion 4, and is radiated from the end portion of the dielectric substrate 1, that is, the opening 13 of each tapered slot antenna portion 11. The opening 1 of each taper slot antenna unit 11
3, the signals whose modes have been converted by the converter 6 are excited in the same phase, and the tapered slot antenna parts 11 are radially arranged as shown in FIG. In the opening 13 of the portion 11, a spherical wave-shaped wave source distribution is formed.

Here, FIG. 2 is an explanatory view of a wave source distribution etc. for explaining a wave source distribution generated in the antenna device etc. shown in FIG. FIG. 2A is an explanatory diagram of the wave source distribution and the wavefront distribution showing the radiation pattern of the antenna device according to the first embodiment, and FIG. 2B is a plan view showing the tapered slot antenna section 11 of the antenna device shown in FIG. It is explanatory drawing, such as a wave source distribution which shows the wave source distribution and its radiation pattern at the time of doing. Figure 2
As shown in (b), in the case of the antenna device in which the taper slot antenna units 11 are arranged in parallel, even if the high frequency signal is distributed to the taper slot antenna units 11 by distributing the same amplitude and phase. The wavefronts are aligned in the opening 13 of the tapered slot antenna unit 11, and the radiation pattern 15 having a narrow beam width is formed. On the other hand, in the antenna device according to the first embodiment, since the taper slot antenna parts 11 are radially arranged,
As shown in FIG. 2 (a), the wavefront shape becomes an arc shape,
Within the angular range of the tapered slot antenna section 11, the wave source distribution is concentric. With such a wave source distribution, the openings 1 of the taper slot antenna parts 11 are formed.
The radio wave radiated from 3 is radiated as a spherical wave as it is, so that a desired radiation pattern in which a drop in gain in a wide angle is prevented, that is, a radiation pattern 16 having a wide beam width over a wide band can be formed.

As described above, according to the antenna device of the first embodiment, the plurality of taper slot antenna units 10 are radially arranged so that the openings 12 of each taper slot antenna unit 10 are arranged in an arc shape. Since the high frequency signals distributed by the distributor 9 are supplied to the plurality of taper slot antenna parts 10, respectively, a concentric circular wave source distribution is formed and spherical radio waves are generated from the openings 12 of the taper slot antenna parts 10. Is emitted. As a result, a drop in gain in a wide angle can be prevented, and a radiation pattern having a wide beam width can be formed over a wide band.

Embodiment 2. Next, a second embodiment of the present invention will be described with reference to FIG. 3 is a configuration perspective view showing an antenna device according to a second embodiment of the present invention. In FIG. 3, reference numeral 17 denotes a fan-shaped biconical antenna portion in which a tapered notch portion 18 is formed in an arc portion, 7b.
Is a slot portion formed to be connected to the tapered notch portion 17 of the biconical antenna portion and extending on the side opposite to the arc portion, and 5b is a feed line for supplying a high frequency signal, 6
b A converter for mode-converting and transmitting the high-frequency signal supplied by the feeder line 5b onto the slot 7b, and 8b is a feeder such as a coaxial connector to which a high-frequency signal from an external device is fed.

The high frequency signal fed to the feeding portion 8b of the fan-shaped biconical antenna portion 17 (hereinafter referred to as the biconical antenna portion 17) having the tapered notch portion 18 is fed to the converting portion 6b via the feeding line 5b. To the slot 7b by the converter 6b.
The signal whose mode has been converted in the converter 6b is transmitted through the slot 7b and the tapered upper notch 18, and is radiated from the arc-shaped end of the tapered upper notch 18, that is, the opening 13b of the biconical antenna 17. . Since the opening 13b of the biconical antenna unit 17 is formed in an arc shape, a concentric wave source distribution similar to that of the antenna device according to the first embodiment shown in FIG. 1 is formed. With such a wave source distribution, the radio wave radiated from the opening 13b of the biconical antenna unit 17 is radiated as a spherical wave, and a desired radiation pattern in which a drop in gain in a wide angle is prevented, that is, a wide band is obtained. It is possible to form the radiation pattern 16 having a wide beam width over the entire area.

As described above, according to the antenna device of the second embodiment, since the opening 13b of the biconical antenna part 17 is formed in an arc shape, a concentric circular wave source distribution is formed, and the biconical antenna is formed. A spherical radio wave is radiated from the opening 13b of the portion 17. As a result, a drop in gain in a wide angle can be prevented, and a radiation pattern having a wide beam width can be formed over a wide band as in the antenna device according to the first embodiment.

Embodiment 3. Next, a third embodiment of the invention will be described. In the third embodiment, an array antenna to which the antenna device as shown in FIG. 1 or 3 is applied will be described. In the second embodiment, the tapered notch portion 18 is formed in the arc portion of the fan-shaped biconical antenna portion 17. However, this die is formed into a cylindrical shape, and the tapered notch portion 18 is formed over the entire circumference. Then, the configuration is similar to that of a general biconical antenna. Since such a biconical antenna can obtain omnidirectionality in the horizontal plane, it is possible to widen the beam width, but since radio waves are radiated in all azimuth directions, this should be applied to a plane array antenna etc. It is difficult. That is, when the biconical antenna is mounted on the mounting surface of the planar array antenna, the omnidirectional antenna naturally has a large back lobe component, and the mounting surface acts as a reflector and depends on the height from the reflector. The phenomenon that the gain drops in a specific direction occurs.

On the other hand, as shown in FIG. 1 and FIG.
In the antenna device according to the present invention shown in FIG. 2, spherical radio waves are radiated only in the angular range of the plurality of taper slot antenna parts 11 or in the angular range of the biconical antenna part 17. When applied to an antenna, etc., the effect of back lobes on the antenna mounting surface on which these antenna devices are mounted can be greatly reduced, and there is no drop in gain within the coverage of a planar array antenna, etc. It is possible to configure an array antenna having a wide beam width capable of covering the above.

FIG. 4 is a partial configuration diagram schematically showing the positional relationship between the antenna mounting surface of the array antenna and the antenna device mounted on the antenna mounting surface. In FIG. 4, 19 is an antenna mounting surface, and 20 is a back lobe. For example, a plurality of antenna devices configured by the biconical antenna unit 17 are mounted on the antenna mounting surface 19 in an array. It should be noted that description of the specific mounting structure of the antenna device and the overall configuration of the array antenna is omitted. As shown in FIG. 4, since the opening 13b of the antenna device is arranged in the direction opposite to the antenna mounting surface 19, the influence of the back lobe on the antenna mounting surface 19 can be significantly reduced, and the planar array antenna It is possible to construct an array antenna having a wide beam width within a desired coverage area without a drop in gain within the coverage area.

More specifically, by setting the angle formed by the line passing through the circular arc portion of the biconical antenna portion 17 within 180 degrees, the influence of the back lobe on the antenna mounting surface 19 and the influence on the adjacent antenna device. Can be significantly reduced. Also when the antenna device according to the first embodiment is applied, the angle between the taper slot antenna portions arranged on both outer sides is set to be 180 degrees or less, so that the influence of the back lobe on the antenna mounting surface 19 and the adjacent antenna devices are reduced. The influence can be significantly reduced.

[0027]

As described above, according to the present invention, an antenna element having a conductor portion formed on a dielectric substrate, and the conductor portion having a tapered slot extending toward an end portion of the dielectric substrate, and the antenna A microstrip line for supplying a high-frequency signal to the element, a taper slot antenna part formed with a conversion part for mode-converting and transmitting the high-frequency signal supplied by the microstrip line on the taper slot, and an end of the dielectric substrate. Since the plurality of taper slot antenna parts are arranged radially so that the parts are arranged in an arc shape, and a distributor for distributing and feeding a high frequency signal to the plurality of taper slot antenna parts is provided, a radiation pattern An antenna device that can prevent wide-angle gain drop and obtain a wide beam width over a wide band Door can be.

According to another aspect of the invention, a fan-shaped biconical antenna portion having a tapered notch portion formed in an arc portion and a tapered notch portion of the biconical antenna portion are connected to each other. A slot portion extending to the opposite side of the circular arc portion, a power feeding line for supplying a high frequency signal to the slot portion, and a converter for mode-converting and transmitting the high frequency signal supplied by the power feeding line to the slot portion. Since the antenna device is provided, it is possible to obtain an antenna device which can prevent the gain from dropping in a wide angle of the radiation pattern and can obtain a wide beam width over a wide band.

According to another aspect of the invention, since the antenna devices as described above are arranged in an array, the influence of the back lobe on the antenna mounting surface of the antenna device can be greatly reduced, and the array antenna is covered. It is possible to obtain an array antenna having a small beam drop within the range and having a wide beam width in a desired coverage area.

[Brief description of drawings]

FIG. 1 is a perspective view showing an antenna device according to a first embodiment of the present invention.

2 is an explanatory diagram of a wave source distribution and the like for explaining a wave source distribution generated in the antenna device and the like shown in FIG.

FIG. 3 is a perspective view showing an antenna device according to a second embodiment of the present invention.

FIG. 4 is a partial configuration diagram schematically showing an arrangement relationship between an antenna mounting surface of an array antenna according to a third embodiment of the present invention and an antenna device mounted thereon.

FIG. 5 is a perspective view showing a conventional antenna device.

FIG. 6 is a radiation pattern diagram schematically showing a radiation pattern of the conventional antenna device shown in FIG.

[Explanation of symbols]

1 dielectric substrate, 2 metal conductor part, 3 antenna element,
4 taper part, 5 microstrip line, 5b feed line 6,6b conversion part, 7,7b slot part,
8 and 8b feeding part, 9 distributor, 11 taper slot antenna part, 13 and 13b opening part, 17 biconical antenna part, 18 taper notch part.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5J021 AA03 AA07 AA10 AA11 AB06                       CA03 FA32 GA08 HA04 HA05                       JA02                 5J045 AA02 AA26 BA02 DA06 EA07                       FA02 GA03 HA03 HA06 JA12                       NA01 NA07

Claims (6)

[Claims] 1. An antenna element having a conductor portion formed on a dielectric substrate, wherein the conductor portion is formed of a taper slot whose slot width is widened toward an end portion of the dielectric substrate, and a micro-frequency signal is supplied to the antenna element. A stripline and a taper slot antenna section forming a conversion section for mode-converting and transmitting the high-frequency signal supplied by the microstripline on the taper slot and an end of the dielectric substrate are arranged in an arc shape. An antenna device comprising: a plurality of the taper slot antenna parts arranged in a radial manner, and a distributor for distributing a high-frequency signal to the plurality of taper slot antenna parts for feeding. 2. The antenna device according to claim 1, wherein the distributor distributes the high-frequency signal fed to the plurality of taper slot antenna units to an equal amplitude and an equal phase. 3. The antenna device according to claim 1, wherein the plurality of taper slot antenna parts are composed of three or more taper slot antenna parts. 4. The plurality of taper slot antenna parts are arranged such that an angle formed between the taper slot antenna parts is within 45 degrees. The antenna device according to any one of claims. 5. A fan-shaped biconical antenna portion having a tapered notch formed in an arc portion, and a side opposite to the arc portion formed so as to be connected to the tapered notch portion of the biconical antenna portion. A slot portion extending to the slot portion, a feeding line for supplying a high frequency signal to the slot portion, and a converter for mode-converting and transmitting the high frequency signal supplied by the feeding line to the slot portion. Antenna device. 6. An array antenna, wherein the antenna device according to claim 1 or 5 is arranged in an array.